Make the Dough: Combine the all-purpose flour, salt, sugar, and baking powder in a large bowl, mixing until the dry ingredients are evenly distributed.
Add the Wet Ingredients: Pour in the vegetable or olive oil, warm water, and warm milk. Mix everything together until a smooth, semi-stiff dough forms. If the dough feels very dry, add a little more water or milk as needed.
Rest the Dough: Allow the dough to rest for about 30 minutes.
Divide the Dough: Lightly dust the work surface with flour. Divide the rested dough into 8 equal portions.
Roll the Rotis: Roll each portion into a disk approximately 6 inches in diameter. Keep the roti neither too thick nor too thin so it cooks properly.
Heat the Pan: Place a tava or flat pan over heat and allow it to become hot before cooking the rotis.
Cook the First Side: Brush the hot pan with butter. Place one rolled roti on the pan and cook until bubbles appear on the surface.
Flip the Roti: Turn the roti over once bubbles develop on the first side. Brush the cooked side with some butter.
Cook Until Golden: Continue cooking until the roti develops a golden-brown color.
Repeat the Process: Continue rolling and cooking the remaining dough portions in the same way, brushing the pan or rotis with butter as needed.
Serve: Serve the Thai Roti Bread hot, traditionally alongside tofu bhurji as suggested in the source.